A radicalised, American-born Pakistani went to Saudi Arabia and married another Pakistani brainwashed with an extremist version of Wahhabism that is the Saudi state religion. The couple came to the US and shot up a Christmas office party killing 14 people.

Guess who is being chosen for punishment for this despicable crime? Iranian Americans, who have never shared that extremist ideology and who, as far as we know, have never had anything to do with this or any other act of terrorism anywhere in the world.

The passage by the United States House of Representatives of the Visa Waiver Improvement and Terrorist Travel Prevention Act, or HR 158, brings to mind a Persian story about a ruler who heard a blacksmith had committed a crime in the city of Balkh, now in northern Afghanistan. In his desire to appear swift in meting out justice he ordered the arrest and beheading of the culprit.

But, as Balkh was too far away, the ruler decreed that beheading any blacksmith would do. And yet his henchmen were unable to find such an artisan in nearby towns. All they found was a coppersmith in the city of Shushtar in western Iran. So, our zealous ruler called for the execution of the poor coppersmith of Shushtar lest the crime of the blacksmith of Balkh went unpunished.

The US House of Representatives just reenacted that story. If backed by the Senate and president, then the new law will bar Iranian-Americans from a 38-nation visa waiver programme that allows visits to signatory countries for up to 90 days without a visa.

Even if we grant that prudence in the cause of security justifies collective punishment, HR 158 does not punish either Pakistani or Saudis dual nationals. Instead Iranian Americans are to be punished – along with dual nationals from Iraq, Sudan and Syria, as well as anyone who has been to any of these four countries in the past five years.

Why? Two reasons. One: somebody had to be nailed. Two: nobody ever pays a political price for targeting Iranian Americans. This is despite the fact no Iranian national, let alone an Iranian American, has ever been proved to be involved in terrorism in the US or Europe – this should not be confused with the state- sponsored assassinations of dissidents by agents of the Islamic Republic that ended in the late 1990s.

So, why do Saudis receive a get-out-of-jail card every time they land on the terrorism square, as they often do? Because they have been the favourites of the American political elites and its ersatz aristocracy including the Bush and Trump dynasties.

Everyone knows that the never-never desert kingdom ruled by the house of Saud was heavily implicated in 9/11. Everyone knows the Saudis have for decades spread the virulent, hardcore ideology of Wahhabism that is now carried by the Taliban, al-Qaida, Isis, Boko Haram, and a dozen other terrorist franchises from Chechnya and Baluchistan to Chad. And yet, the Saudis appear untouchable.

The kabuki of passing HR 158 was an elaborate show that made the House of Representatives look busy without having the slightest effect on the security of US citizens. The legislation would restrict the travel of people who have nothing to do with terrorism but let the most likely suspects continue their movement without restrictions.

The HR 158 would affect people who have travelled directly between the US and Syria, missing the glaring fact that virtually nobody actually does this: Isis recruits usually go back and forth via Turkey. Why not introduce travel restrictions for people who go there? Because Turkey is a member of Nato and confronting them would be costly.

This is an old story. Iranians had nothing to do with 9/11 while the Saudis supplied 15 out of 19 hijackers of that bloody Tuesday.

But it was not the student visas of Saudi nationals but those of Iranians that were restricted after those attacks. It appears that we are perfect scapegoats again. Unable to find the blacksmith of Balkh, the House wants to chop off the head of the coppersmith of Shushtar.

The Tehran Bureau is an independent media organisation, hosted by the Guardian. Contact us @tehranbureau